Support Thunderbird

[bastik-1001]

Thunderbird has support for WebSockets, (Thunderbird 17 has them enabled by default). Some people users browsers for which an add-on to support Flash proxy is not available, though the may use Thunderbird.

Thunderbird uses the same engine as Firefox so it should work, especially as the JS is now included in the add-on.

It might be only a simple change in the .rdf file.

[bastik-1001]

According to
https://developer.mozilla.org/en-US/docs/Extensions/Thunderbird/Building_a_Thunderbird_extension_3:_install_manifest
the em:id for Thunderbird is

//<//em:id//>//{3550f703-e582-4d05-9a08-453d09bdfdc6}//<///em:id//>//

[reezer]

I will consider this blocked by upstream for now. It would be possible to use a more low level API, but I don't have the time for this now. However once the following upstream bug is fixed I am of course going to support that.

https://bugzilla.mozilla.org/show_bug.cgi?id=724276

[bastik-1001]

Patching the .rdf file is not an option here either. Installing works, but there's the same(?, at least similar) error as for #7

I'll be available for testing and since I'm using Thunderbird I'll see how new versions perform almost automatically.